A sign indicating 'Narrow bridge ahead' is warning drivers about what?

The sign indicating 'Narrow bridge ahead' serves to alert drivers that the bridge they are approaching has a reduced width, which may not safely accommodate larger vehicles. This information is crucial for ensuring safety, as drivers need to be aware that their vehicle's size could pose a risk when crossing the bridge.

When a vehicle that exceeds the width of the bridge attempts to cross, there may not be sufficient space to do so safely, potentially leading to accidents or blockages. Therefore, it is essential for drivers, especially those operating larger vehicles, to take caution and possibly choose an alternative route if necessary. Understanding the implications of the sign helps drivers make informed decisions about their travel and ensures the safety of all road users.